Treatment for erythropoietic protoporphyria

ORIGINAL ARTICLE, p 1601 Biolcati et al. present the results of a programme in Switzerland and Italy that provides patients with erythropoietic protoporphyria (EPP) with access to afamelanotide, a new orphan drug.1 Afamelanotide is an analogue of α‐melanocyte stimulating hormone (α‐MSH), which is given as a delayed release subcutaneous implant every 2 months. Afamelanotide stimulates the production of eumelanin, which blocks the penetration of photosensitizing blue light, and increases the tolerance of patients with EPP to sunlight.2 The beneficial effects are possibly due to more than simply reducing penetration of light into the skin. Eumelanin also functions as a scavenger of free radicals and, together with α‐MSH, plays a role in suppressing immune and inflammatory reactions in the skin. The mechanism of action is unusual for a new drug for an orphan disease, in that it is not aimed at changing the underlying metabolic abnormality, but at preventing and reducing the most troublesome manifestations. Afamelanotide does not change protoporphyrin IX levels and is unlikely to influence other rare complications of EPP such as anaemia and liver disease.